In northern climates, snowplows wider than the standard plows used on highways and surface streets are required for the plowing of large areas such as parking lots and airport runways. As such, it is desirable to be able to plow as wide a swath as possible in one pass to minimize the time it takes to complete the plowing of an area. This can especially be the case for airport runways, where for safety reasons snow removal crews must adhere to guidelines on permissible snow accumulations, and time spent by an airliner sitting on a taxiway awaiting the removal of snow from a runway is highly expensive.
A traditional method of plowing a wide swath has simply been to maximize the width of a host vehicle mounted fixed blade. The problem is that maximizing blade widths is in direct conflict with a need to minimize that same blade for safe transport between worksites. With most snowplows typically mounted to multipurpose vehicles such as front-end loaders, wide blades cannot safely be driven from one site to another. In order to use such a wide fixed-blade plow at more than one site, it must be transported from one location to another separate from its host vehicle, such as on a flatbed truck.
Prior art blades have over the years provided a snowplow with a wide plowing profile that is adjustable from an open configuration for plowing, to a closed configuration for inter-site transport while still mounted to its host vehicle. To achieve this, various blade configurations have been devised to change the configuration of the blade from a minimized to a maximized width and back again. One variation involves telescoping wings that extend longitudinally beyond a main blade. These however involve complex components, and are prone to clogging and icing up.
Another variation involves the retracting of wing blades to the rear of a main blade for stowage during transport. The problem with this rearward-retracting configuration is that the wing blades must be tucked behind the main blade and are therefore in front of and adjacent to the tires of the host vehicle, making the retracted position of the wing blades proximal to the tires, thus creating a safety hazard. What is needed is a snowplow that provides a wide plowing profile as well as providing a compact transport profile and that also maintains the adjustable blades at a safe distance from the tires at all times. In addition, it would be advantageous to provide such a retracting blade in a more rigid design, to overcome the problems of prior art variable-width blades and their inherent lack of strength and stability. It should be noted that such a blade could readily be used for plowing materials other than snow, such as sand or gravel.
For the foregoing reasons, there is a need for an improved plow.